1. Field of the Invention
Embodiments of the present invention generally relate to a phototherapy device and, more particularly, to methods of providing uniform distribution of light in a phototherapy device.
2. Description of the Prior Art
Phototherapy is a promising clinical tool for the treatment of many conditions, including seasonal affective disorder, bulimia nervosa, herpes, psoriasis, sleep disorders, acne, and skin cancer.
Phototherapy is especially promising as a treatment for hyperbilirubinemia, a common condition affecting 70% of all full-term infants. Hyperbilirubinemia is caused by the accumulation of excess bilirubin in the blood and skin of the infant. This excess bilirubin turns the skin and sclera a characteristic yellow color. If left untreated, extreme cases of hyperbilirubinemia can result in neurological insult (kernicterus) or even death. A common treatment for hyperbilirubinemia is phototherapy, in which the infant is exposed to light in a range corresponding to the peak absorption spectra for bilirubin (blue-green 0-520 nm). This light changes the form of the bilirubin to a different isomer that is more readily eliminated by the body.
A number of different light sources can be used for phototherapy. Traditionally, broadband sources have been used, such as fluorescent, halogen, or incandescent light. However, it has been recently suggested that light-emitting diodes (LEDs) can be an effective phototherapeutic light source.
When using LEDs, multiple devices may be necessary to ensure proper surface area coverage. When using banks of LEDs, caregivers must ensure that the intensity delivered to the entire surface area is within the effective intensity range. The international standards governing phototherapy systems, state that peripheral intensity must equal or exceed 40 percentage of the peak intensity. When measuring the irradiance, caregivers should take measurements at multiple points along the treatment area to verify that their device meets these standards.
The current method used for optimizing the type of LED, number of LEDs and location of LEDs for achieving peak irradiance and desired spectral irradiance distribution involves physical testing, which is time consuming.
Therefore, towards improving the application of effective phototherapy, there is a need to develop an efficient, reliable and user-friendly method of optimizing the positioning of LEDs for achieving peak irradiance and uniform spectral irradiance distribution.